Finally: A function call that runs at the end of a scope to tear things down.

finally.h

#ifndef FINALLY_H
#define FINALLY_H

#include <utility>

template<class Lambda>
class Finally {
public:
  Finally(Lambda &&func): func_(std::forward<Lambda>(func)) {};
  ~Finally() { func_(); };
private:
  Lambda func_;
};

template<class Lambda>
Finally<Lambda> make_finally(Lambda &&func) {
  return { std::forward<Lambda>(func) };
}

#endif // FINALLY_H

main.cpp

// Compile by `$ g++ main.cpp`
#include "finally.h"

#include <cstdlib>
#include <iostream>

using std::cout;
using std::endl;

int main() {
  int* data = (int*) calloc(1, sizeof(int));
  *data = 3141592;
  
  auto finally = make_finally([data] {
    cout << "Run the following code before going out this scope." << endl;
    cout << "Free data " << *data << endl;
    free(data);
  });

  cout << "Do something here first..." << endl;

  return 0;
}